In July 1956, a plane crashed in Suffolk, nearly detonating an atomic bomb. In
January 1987, an RAF truck carrying hydrogen bombs skidded off a road in
Wiltshire. Other near-misses remain top secret. Who is really at risk from
Britain's nuclear weapons?

'Secrecy surrounding British nuclear weapon accidents has exceeded even that of the US.' Illustration: Noma Bar

In October of 1983, Mick Jones had just left the Clash,
Roger Moore was still playing James Bond,
Ronald Reagan was in his third year as president of the US,
Margaret Thatcher had recently gained a second term as prime minister –
and the cold war had entered its most dangerous phase since the Cuban missile
crisis. An all-out nuclear exchange between the US, the Soviet Union and their
allies seemed possible. That spring, Reagan had called the Soviets "the focus
of evil in the modern world… an evil empire", and his administration was
conducting an unprecedented military buildup during peacetime. Yuri Andropov,
the terminally ill, deeply paranoid leader of the Soviet Union, thought the US
might be planning a surprise attack. In September,
Korean Airlines Flight 007, a Boeing 747 carrying almost 300 passengers,
had been shot down after straying into Soviet airspace. The US was about to
deploy two new nuclear weapon systems: ground-launched cruise missiles in the
UK and Pershing II missiles in West Germany. And on 22 October, almost
a quarter of a million people marched in Hyde Park to protest against those
deployments, the largest anti-nuclear demonstration in British history.

Amid that ominous, apocalyptic mood, the Reagan administration decided to
build a new submarine-launched ballistic missile. The Trident D5 would be the
most accurate missile ever carried by a sub, capable of sending eight nuclear
warheads halfway across the world to destroy "hard targets": Soviet missile
silos and leadership bunkers. Unlike previous submarine-launched missiles, the
Trident D5 wasn't designed solely as a retaliatory weapon, to be used
after the US had been hit by a nuclear attack. The new missile could be
launched against the Soviet Union as part of an American first strike.

Thirty years later, the cold war is a distant memory, the Soviet Union is
gone, Reagan and Thatcher are gone – and a British Trident submarine is still
continuously at sea, day and night, waiting for the order to fire its D5
missiles and dozens of nuclear warheads. Over the next few years, Britain will
have to decide whether to replace its four ageing Trident submarines.
David Cameron wants to build four new subs, at a cost of about £25bn, so
that one will always be at sea, safe from attack and prepared to launch.
The Labour party seems to endorse that policy: its shadow defence
secretary, Jim Murphy, recently expressed support for "a continuous at sea
deterrent". Though the Liberal Democrats have criticised Cameron's position,
their preference hardly seems radical: building one, or perhaps two, fewer
submarines in order to save money. The three main parties are broadly agreed
on the need for nuclear weapons. The strongest opposition to Trident comes
from politicians in Scotland, where the submarines are based.
Alex Salmond, head of the SNP, has promised that if Scotland gains
independence next year, its new constitution will include a ban on all nuclear
weapons. This could be disastrous for the UK's nuclear deterrent: building a
new submarine base and weapon storage facilities in England would take many
years and cost tens of billions.

The public debate about Britain's Trident submarines and their missiles has
focused mainly on the long-term costs and economic benefits of replacing them,
the number of jobs that might be gained or lost, the necessity of
round-the-clock patrols. Some fundamental questions have been largely absent
from the discussion. How would this cold war missile, due to remain in service
for another 30 years, actually be used in a 21st-century conflict? What
targets would it destroy and in what circumstances? Whom is it supposed to
kill? Finally, and perhaps most importantly, do the British people face a
greater chance of being harmed by their own nuclear weapons, through an
accident or a mistake, than by a surprise attack?

In Grand Forks, North Dakota, in September 1980, a B-52
bomber loaded with 12 hydrogen bombs and nuclear warheads caught fire. It
burned for two hours, fed by a fuel pump. Only gale force winds blowing the
flames away, and a fireman climbing on to the burning plane to shut off the
power, averted disaster.

"The credibility of the UK's deterrent is crucial," the government's
Trident Alternatives Review declared in July this year. On a single page
of the report, the words "credible" or "credibility" are used seven times to
describe the British nuclear strategy of "minimum deterrence". But the report
never says who is to be deterred, and what the UK would actually do with its
nuclear weapons should that deterrence fail. The
2010 Strategic Defence And Security Review mentions the risk of "nuclear
terrorism" and "the possibility that a major direct nuclear threat to the UK
might re-emerge". The implication is that North Korea, China, Pakistan, Iran
or Russia might one day seek to wipe out London, despite the sizable
investments some of those countries have made in the city. But the security
review doesn't explain in what circumstances Britain's Trident missiles would
ever be launched, citing the need to remain "deliberately ambiguous".

Since the dawn of the atomic era, the sort of ambiguity deemed essential to
confuse potential enemies has enabled government officials to avoid domestic
oversight and accountability. A few weeks ago, parliament voted to prevent
Cameron from authorising a relatively small British attack on Syria, yet
a British prime minister can authorise a nuclear attack that might kill
millions without public approval or parliamentary debate. The intense secrecy
that surrounds nuclear war planning has hidden not only the devastation that
would be inflicted upon targets, but also the grave dangers posed by a
nation's own weapons, the risk of serious accidents. And whenever
those nuclear secrets are revealed, however incompletely, plans that were
thought "credible" by those in power usually seem incredible,
almost unbelievable, to everyone else.

Nuclear weapons are the most lethal machines ever invented, but the
deterrence they provide is something intangible. "The central objective of a
deterrent weapon system… is psychological," a classified Pentagon report once
explained. "The mission is persuasion." The destruction of
Hiroshima and
Nagasaki showed what a single atomic bomb could do to a city. But
widespread revulsion at the civilian casualties prompted the US to explore how
nuclear weapons might be used against traditional military targets.

In 1946, the US conducted its first postwar tests of the atomic bomb. One
of these tests sought to discover the effect of a nuclear blast on a fleet of
warships. The results were discouraging. Of the 88 ships moored near
the point of detonation, in the Bikini atoll, only five sank.
The Evaluation Of The Atomic Bomb As A Military Weapon, a top-secret
report sent to Harry Truman, concluded that "ships at sea" and "bodies of
troops" were poor targets. "The bomb is pre-eminently a weapon for use against
human life and activities in large urban and industrial areas," the report
argued. Such weapons were useful, most of all, for killing and terrorising
civilians. According to the report, some of the best targets were "cities of
especial sentimental significance".

America's first nuclear war plan, adopted in 1948 and codenamed Halfmoon,
called for 50 atomic bombs to be dropped on the Soviet Union. The number was
subsequently increased to 133, aimed at 70 cities. Leningrad was to be hit by
seven bombs, Moscow by eight. There seemed no alternative to the threat of
mass slaughter. This US strategy was called "the nation-killing concept".

At congressional hearings in October 1949, the US had its most publicised,
high-level debate about the ethics of such nuclear targeting. A group of
admirals strongly condemned the war plan the US air force intended to use
against the Soviets. "I don't believe in mass killings of noncombatants,"
Admiral Arthur W Radford testified, while
Rear Admiral Ralph A Ofstie, who had toured the burnt-out cities of Japan,
described the atomic blitz as "random mass slaughter of men, women and
children", and said the whole idea was "ruthless and barbaric", contrary to
American values.

By the mid-1950s, the American war plan had shifted from hitting "countervalue" targets (cities) to destroying "counterforce" targets (military facilities).
The invention of the hydrogen bomb had created nuclear weapons hundreds of times more powerful than the bomb that destroyed Hiroshima. The Soviet Union
now had its own nuclear weapons, and destroying them became the air force's principal goal.

In December 1960, the US approved its first Single Integrated Operational Plan (Siop), which specified the timing and targeting of attacks to be
conducted by US forces and UK Bomber Command. This plan, in one form or another, would remain in effect for more than three decades. Most of Siop's
details remain classified, but memos written during John F Kennedy's administration, at the height of the
Berlin crisis in 1961, give a sense of how much destruction the Siop would
unleash. It featured 3,729 targets that would be struck by 3,423 nuclear weapons. The targets were located in the Soviet Union, China, North Korea and
eastern Europe. About 80% were military targets, the rest civilian. Of the "urban-industrial complexes scheduled for destruction", 295 were in the Soviet
Union and 78 in China.

The Siop's damage and casualty estimates were conservative. They were based solely on blast effects, and excluded the harm that might be caused by thermal
radiation, fires or radioactive fallout, which was difficult to calculate. Within three days of an initial attack by the US and UK, the full force of the
Siop would kill about 54% of the Soviet Union's population and about 16% of China's population: roughly 220 million people. Millions more would
subsequently die from burns, radiation poisoning and exposure.

Britain's nuclear war plans were never as conflicted as those of the US. Within weeks of Hiroshima's destruction,
Clement Attlee succinctly expressed what would become the British
philosophy: "The answer to an atomic bomb on London is an atomic bomb on another great city." Britain lacked the means to build enough nuclear weapons
to threaten thousands of military targets in the Soviet Union. And the British population wasn't widely dispersed across a large continent. In 1955, a secret
report by William Strath, an official at the Central War Plans Secretariat, concluded that if 10 hydrogen bombs were detonated along the west coast of the
UK, the ensuing firestorms and radioactive fallout would immediately kill or wound about one-third of the British population. Most of the nation's farmland
would be unusable for two months, and drinking water would be contaminated. Even if Britain somehow managed to destroy most of the Soviet Union's nuclear
arsenal, a handful of Soviet weapons could cause much of British society to collapse.

In 1958, Bomber Command's emergency war plan called for the destruction of
44 Soviet cities. Such an attack would kill about 38 million people. One
hydrogen bomb would be dropped on the centre of each city, but Moscow would be
hit by four and Leningrad by two. Had Britain gone to war alongside the US in
the early 1960s, Bomber Command would have been asked to destroy an additional
25 Soviet cities. As air defences improved in the Soviet Union, the number of
urban areas that Britain planned to destroy unilaterally was reduced. By the
late 1960s, the missiles carried by Polaris submarines served as the British
strategic deterrent, and they were aimed at fewer than a dozen Soviet cities.
Until the end of the cold war, the complete destruction of the Soviet Union's
capital – known as the "Moscow criterion" – was the UK's main objective.

The Joint Intelligence Committee assumed that Soviet war plans would be
even more brutal. According to its report on "Probable Nuclear Targets In The
United Kingdom", London would be hit by eight hydrogen bombs and two atomic
bombs. Edinburgh would be hit by two of each, Glasgow by four hydrogen bombs
and one atomic bomb, while the British submarine bases in Scotland would be
hit by four hydrogen bombs and four atomic bombs. All in all, the JIC expected
that during a war with the Soviet Union, the UK would be struck by about 300
nuclear weapons.

Faslane naval base on the Clyde. Scotland is home to both
Britain’s Trident submarines and the strongest opposition to them, with SNP
leader Alex Salmond vowing to ban them if Scotland gains independence. This
could be disastrous for the UK’s nuclear deterrent: building a new base would
take years and cost billions. Photograph: Murdo Macleod

Strict official secrecy has enabled British and American war planners to
choose their targets without public scrutiny. It has also facilitated the
management of public opinion about nuclear weapons.
The Strath report was suppressed, and
Winston Churchill ordered the BBC not to broadcast news about the hydrogen
bomb that might scare people. From Attlee's decision to build a British atomic bomb to
James Callaghan's negotiations to obtain Trident missiles from the US,
British nuclear policy has been carried out without much parliamentary oversight. "All of the key nuclear decisions were taken by a small number of
very senior government ministers, meeting in informal ad hoc committees," the historians John Baylis and Kristan Stoddart have noted. "These decisions had
been kept secret from the main cabinets of the day."

In the US, the design specifications of nuclear weapons don't even have to be classified. According to
the Atomic Energy Act of 1946, they are "born secret": classified as soon
as they exist. Maintaining secrecy about nuclear weapon designs may seem like
common sense, but the secrecy justified by a need to prevent foreign espionage
has routinely been used instead to hide safety problems, cover up nuclear
weapon accidents and shield defence bureaucracies from embarrassment.

The Pentagon's official list of "broken arrows" – mishaps with nuclear
weapons that might threaten the public – mentions 32 accidents. Yet a 1970
study by one of America's nuclear weapon laboratories, obtained through the
Freedom of Information Act, stated that at least 1,200 weapons were involved
in accidents between 1950 and 1968. Most of these accidents were trivial, but
a number of serious ones were somehow omitted from the Pentagon's list.
Moreover, the risk of accidental nuclear detonations was not fully understood
by American weapon designers until the late 1960s, and it proved far greater
than expected. A plane crash, a fire, a missile explosion, lightning, human
error, even dropping a weapon from an aircraft parked on a runway were found
to be potential causes of a nuclear explosion.

Two of the more dangerous accidents occurred in one month. On 15 September
1980, one of the engines on a B-52 bomber caught fire at Grand Forks air force
base in North Dakota. The plane was carrying four hydrogen bombs and eight
short-range missiles with nuclear warheads. A strong wind kept the flames away
from the weapons, and a fireman climbed into the burning plane, put out the
fire, and averted a disaster. Three days later a technician dropped a tool in
the silo of a Titan II intercontinental ballistic missile near Damascus,
Arkansas. The tool hit the bottom of the silo, bounced, struck the side of the
missile, pierced the skin and caused a fuel leak. The Titan II was carrying
the most powerful nuclear warhead ever built by the US. Despite a heroic
effort to save the missile, it exploded – but the warhead didn't detonate.
Both states could have been destroyed.

The safety problems with American nuclear weapons were kept secret until
the conclusion of the cold war. A study later sponsored by the US Congress
gave a "safety grade" to each type of nuclear weapon in the nation's arsenal.
The grades were based on the potential risk of accidental detonation or
plutonium scattering. Three weapons received an A. Seven received a B. Two
received a C-plus. Four a C. Two a C-minus. And 12 received a D, the lowest
grade.

The safety issues with American nuclear weapons had implications far beyond
US borders. Nato forces relied on many of them. For years, the number of
American nuclear weapons deployed in Britain exceeded the number of British
ones. According to the historian John Simpson, in 1959 the RAF had 71 British
atomic bombs and 168 American ones. In the years that followed, the nuclear
weapons manufactured in Britain became remarkably similar to those made in the
US, thanks to the US-UK Mutual Defence Agreement.
The design of "Red Snow", the nuclear component at the heart of Britain's first widely
deployed hydrogen bomb, was based on that of the American Mark 28 bomb. In 1961,
Harold Macmillan was told British weapon development was "confined almost
entirely to copying US designs".

The secrecy surrounding British nuclear weapon accidents has exceeded even
that employed to hide US ones. In July 1992, a report by Sir Ronald Oxburgh,
the chief scientific adviser at the Ministry of Defence, claimed that 19
accidents had occurred with British weapons between 1960 and 1991. The Oxburgh
report suggested that none of the accidents was particularly worrisome, and
according to the Ministry of Defence, the UK has no record of any accidents
involving US weapons on British soil. However, while researching safety
problems with American nuclear weapons, I came across information about
serious British accidents that weren't mentioned by Oxburgh.

Two of the accidents occurred at RAF Lakenheath. On 27 July 1956, an
American B-47 bomber was practising touch-and-go landings. The plane veered
off the runway and slammed into a storage igloo containing Mark 6 atomic
bombs. An American officer who witnessed the accident described what happened
next in a classified telegram: "The B-47 tore apart the igloo and knocked
about 3 Mark Sixes. A/C [aircraft] then exploded showering burning fuel
overall. Crew perished. Most of A/C wreckage pivoted on igloo and came to rest
with A/C nose just beyond igloo bank which kept main fuel fire outside smashed
igloo. Preliminary exam by bomb disposal officers says a miracle that one Mark
Six with exposed detonators sheared didn't go. Firefighters extinguished fire
around Mark Sixes fast."

The nuclear cores of the weapons were stored in a different igloo. If the
B-47 had hit that igloo instead, a large cloud of plutonium could have floated
across the Suffolk countryside. Plutonium dust can be lethal when inhaled.
Once dispersed, it is extremely difficult to clean up, and it remains
dangerous for about 24,000 years.

Another bad accident occurred at Lakenheath on 16 January 1961. The
under-wing fuel tanks of a US F-100D fighter were mistakenly jettisoned when
the pilot started the engines. The fuel tanks hit the runway and ruptured,
some fuel ignited, and a Mark 28 hydrogen bomb mounted beneath the plane was
engulfed in flames. Firefighters managed to extinguish the fire before the
bomb was badly damaged. A flaw in the wiring of Mark 28 hydrogen bombs, it was
later discovered, could allow excessive heat to circumvent the weapon's safety
mechanisms and cause a nuclear detonation.

The safety of the Trident D5 missile has long been a source of concern. In
December 1990, the Panel on Nuclear Weapons Safety, a group of eminent
physicists appointed by the US Congress, warned that its unusual design posed
significant risks. To save space, the multiple warheads weren't mounted on top
of the missile; they surrounded its third-stage rocket engine. And the
"high-energy" class 1.1 propellant used in that rocket engine was far more
likely than other propellants to explode in an accident. "The safety issue of
concern here," the panel found, "is whether an accident during handling of an
operational missile – viz, transporting and loading – might detonate the
propellant which in turn could cause the HE [high explosives] in the warhead
to detonate, leading to dispersal of plutonium, or even the initiation of a
nuclear yield."

The decision to use the more energetic rocket fuel and the more unstable
high explosive was made during the early 1980s, to increase the range of the
Trident D5 missile and decrease the weight of its warheads. The first British
Trident submarine went on patrol four years after these safety risks were
discovered, and the Trident D5 missile is supposed to remain in service until
2042. The risk of explosion and plutonium dispersal is greatest when the
warheads are being loaded on to the sub, unloaded from the sub, or transported
by road between Scotland and the Atomic Weapons Establishment in Aldermaston,
Berkshire.

The worst accident to occur during the handling of nuclear weapons in the
UK, according to the Oxburgh report, came on 7 January 1987, when an RAF truck
swerved to avoid another vehicle on an icy Wiltshire road. The truck, which
was carrying two hydrogen bombs, went off the road and skidded on to its side.
An RAF truck behind it, carrying another two bombs, went off the road, too.
None of the weapons was damaged. But a recently declassified US document
contains details about another serious incident in the UK, and others like it
have no doubt occurred. On 17 August 1962, at an undisclosed RAF base
somewhere in England, two retrorockets on a Thor missile suddenly fired while
it was undergoing a routine check. The launch pad was evacuated, and when
workers returned, they found that the missile's nose cone, containing the
warhead, had not been dislodged. The warhead was about 60 times more powerful
than the bomb that destroyed Hiroshima. "The cause of the incident," the
report noted, "was failure to follow prescribed safety rules."

'A US study gave a "safety grade" to every nuclear weapon in
the nation's arsenal. Twelve received a D, the lowest grade.'

The US has vastly reduced the number of its strategic nuclear weapons, by
almost 90% since the Reagan era. The Siop has been replaced by another set of
targets, known as the Operations Plan (OPlan) 8010, most likely designed to
use nuclear weapons against Russia, China, North Korea, Syria and Iran.
"Adaptive planning" allows targets in other countries to be chosen at the last
minute. In June, the Obama administration publicly released
a new Nuclear Weapons Employment Strategy. It claims that the US would use
nuclear weapons only against military targets and "will not intentionally
target civilian populations or civilian objects". One of the faults with such
a counterforce strategy is that it can make nuclear weapons seem like
legitimate weapons for use in a military campaign. Even the most accurate
nuclear strike will cause collateral damage and lethal radioactive fallout.

As the late
Michael Quinlan, a former permanent secretary at the Ministry of Defence,
observed after the cold war, British war plans seemed to acquire a "very
general 'to-whom-it-may-concern' character". The 2010 Strategic Defence and
Security Review confirmed his opinion: "No state currently has both the intent
and the capability to threaten the independence or integrity of the UK." The
review called Britain's policy of minimum nuclear deterrence an "ultimate
insurance policy" in "an age of uncertainty", without specifying how or
against whom. And there was no mention that such a policy has traditionally
emphasised the destruction of cities, not military forces.

It may indeed be necessary to threaten millions with annihilation in order
to deter a nuclear attack on the UK. That argument, however, should be based on more than the trustworthiness of elected officials. Under the
1962 Nassau Agreement, which first granted the UK the use of US
submarine-based missiles, those weapons were to be employed solely on behalf
of Nato, unless the British government felt that its "supreme national
interests are at stake". The meaning of that phrase has never been explained,
and no prime minister has plausibly described a situation in which the UK
would have to use its nuclear weapons unilaterally, without any support from
the US or the rest of Nato. An attack that wiped out London, for example,
would also kill one or two hundred thousand Americans. Over the past decade,
the US has waged two wars, at a cost of almost $2tn, to avenge the death of
many fewer.

The only word used more often than "credible" in official British
statements on nuclear deterrence is "independent". But the Trident D5 missiles
on British submarines are not, specifically, owned by the UK. They are
supplied from a common Anglo-American pool, returned to the US for
refurbishment and replaced with other missiles. Almost half a century ago,
Harold Wilson raised questions about the "so-called independent, so-called
British, so-called deterrent". Those questions have never been adequately
answered.

Maintaining deliberate ambiguity about nuclear war plans is a good way for
government officials to stifle meaningful debate. And while other pressing
national issues may dominate the news, this one could not be more important.
Britain has never had a full, vigorous debate about its nuclear weapons, based
upon the facts. As other countries seek weapons of mass destruction, the
stakes couldn't be higher. Will new Trident submarines protect the UK or
jeopardise its future? I hope the British people get to decide.

Command And Contol, by Eric Schlosser, is published by Allen Lane, priced £25. To order a copy for £20, with free UK
p&p, go to theguardian.com/bookshop.